对于STM32F764,我希望通过SPI以只读模式从11个菊花链24位ADC接收33字节。接收到的数据看起来没问题,但缓冲区中有 37 到 39 个字节。此外,对于其他字节号,我收到的字节比预期的多 4 到 6 个字节。
有谁知道为什么会这样?
当 33 个字节准备就绪时,HAL_SPI_Receive_DMA由来自外部 ADC 的 GPIO 中断调用。完成 DMA 后,缓冲区内容在 Sampling(( 中处理。
外部 GPIO 中断处理程序是否是调用HAL_SPI_Receive_DMA的正确位置?
/*SPI init for external ADCs (only Rx)*/
uint8_t SPI3_Init_ADC(void)
{
hspi3.Instance = SPI3;
hspi3.Init.Mode = SPI_MODE_MASTER;
hspi3.Init.Direction = SPI_DIRECTION_2LINES_RXONLY;
hspi3.Init.DataSize = SPI_DATASIZE_8BIT;
hspi3.Init.CLKPolarity = SPI_POLARITY_LOW;
hspi3.Init.CLKPhase = SPI_PHASE_1EDGE;
hspi3.Init.NSS = SPI_NSS_SOFT;
hspi3.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_4; /*SPI3_CLK = 12.5 MHz*/
hspi3.Init.FirstBit = SPI_FIRSTBIT_MSB;
hspi3.Init.TIMode = SPI_TIMODE_DISABLE;
hspi3.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
hspi3.Init.CRCPolynomial = 7;
hspi3.Init.CRCLength = SPI_CRC_LENGTH_DATASIZE;
hspi3.Init.NSSPMode = SPI_NSS_PULSE_DISABLE;
if (HAL_SPI_Init(&hspi3) != HAL_OK)
return ERR;
return OK;
}
/*SPI MSP and DMA Initialization*/
void HAL_SPI_MspInit(SPI_HandleTypeDef* hspi)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/*SPI3: ADCs*/
if(hspi->Instance==SPI3)
{
__HAL_RCC_SPI3_CLK_ENABLE(); /* Peripheral clock enable */
__HAL_RCC_GPIOB_CLK_ENABLE();
/*PB3 --> SPI3_SCK*/
/*PB4 --> SPI3_MISO*/
GPIO_InitStruct.Pin = GPIO_PIN_3|GPIO_PIN_4;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF6_SPI3;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
/*DMA 1 / channel 0 / stream 0 transfers data from external ADC to sample registers*/
__HAL_RCC_DMA1_CLK_ENABLE(); /*DMA clock*/
hdma_spi3_rx.Init.Channel = DMA_CHANNEL_0;
hdma_spi3_rx.Init.Direction = DMA_PERIPH_TO_MEMORY; /*from SPI to memory*/
hdma_spi3_rx.Init.PeriphInc = DMA_PINC_DISABLE; /*no increment on SPI side*/
hdma_spi3_rx.Init.MemInc = DMA_MINC_ENABLE; /*increment sample memory address*/
hdma_spi3_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
hdma_spi3_rx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
hdma_spi3_rx.Init.Mode = DMA_NORMAL;
hdma_spi3_rx.Init.Priority = DMA_PRIORITY_VERY_HIGH;
hdma_spi3_rx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
hdma_spi3_rx.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_HALFFULL;
hdma_spi3_rx.Init.MemBurst = DMA_PBURST_SINGLE;
hdma_spi3_rx.Init.PeriphBurst = DMA_PBURST_SINGLE;
hdma_spi3_rx.Instance = DMA1_Stream0;
HAL_DMA_Init(&hdma_spi3_rx);
HAL_NVIC_SetPriority(DMA1_Stream0_IRQn, 0, 0); /*highest priority for DMA interrupt*/
HAL_NVIC_EnableIRQ(DMA1_Stream0_IRQn); /*enable DMA interrupt*/
__HAL_LINKDMA(hspi, hdmarx, hdma_spi3_rx); /*link DMA1 to SPI3*/
}
/*INTERRUPT HANDLERS*/
/*Data ready interrupt (/ADC_/DRDY) of external ADCs*/
void EXTI9_5_IRQHandler(void)
{
HAL_GPIO_EXTI_IRQHandler(GPIO_PIN_7); /*clear interrupt*/
HAL_SPI_Receive_DMA(&hspi3, SplRxBuff, 33); /*get 33 bytes ADC data*/
}
/*DMA1 stream0 global interrupt (Rx of external ADCs complete)*/
void SPI_DMA_Rx_IRQHandler(void)
{
HAL_DMA_IRQHandler(&hdma_spi3_rx);
Sampling();
}
截图:
红色部分是多余的数据。ADC从其未使用的第12个通道提供实际数据。
我敢打赌,因为您没有使用任何同步机制(标志,信号量等(保护启动传输函数调用,因此在其他传输完成之前会触发中断。此外,DMA 处理程序中的神秘函数采样可能会做一些奇怪的事情。